Long-Distance Walking Ups Gray Matter Volume

Older adults who walk at least 72 blocks per week less likely to have cognitive decline

By Eric Metcalf

HealthDay Reporter

THURSDAY, Oct. 14 (HealthDay News) -- In older adults, more physical activity is associated with greater gray matter volume years later, which in turn is linked to a lower risk of cognitive impairment, according to research published online Oct. 13 in Neurology.

Kirk I. Erickson, Ph.D., of the University of Pittsburgh, and colleagues analyzed data from 299 adults ages 65 and older who reported at baseline the total number of blocks they walked in a week. Subjects underwent magnetic resonance imaging nine years later, at which point they were all cognitively normal, and were assessed again for cognitive impairment at 13 years.

The researchers found that more physical activity was associated with greater volumes in the frontal, occipital, entorhinal, and hippocampal regions at nine years. Subjects needed to walk 72 blocks per week before increased gray matter volume was detectable. Increased gray matter volume with physical activity lowered the risk of cognitive impairment twofold, according to the authors.

"First, greater amounts of PA (physical activity) are predictive of greater GM (gray matter) volume 9 years later. Second, walking relatively long distances (72 blocks or roughly 6-9 miles per week depending on the city) was necessary to detect differences in GM 9 years after the baseline evaluation of PA. Third, greater GM in the inferior frontal gyrus, the hippocampus, and the supplementary motor area was associated with a reduced risk of developing cognitive impairment (MCI or dementia)," the authors write.

A co-author disclosed relationships with several pharmaceutical companies.